Could this be the oldest recorded use of stone balls? Fascinating article on the National Geographic web site - click on the link.
http://news.nationalgeographic.com/news/2010/12/101210-stonehenge-balls-ball-bearings-science-rolled

The Stoneballs Company blog is a way in which we can share with you a plethora of interesting , unusual (and sometimes mundane but always pertinent) garden tips, facts, objects, stories and anything to do with gardens, landscapes and of course balls which has caught our interest. We hope you share our enthusiasm and interest!